1. Field of the Invention
The present invention relates to a heating apparatus which can be controlled by voice command rather than by the pushing many switch buttons.
2. Prior Art
In a heating apparatus, a heating sequence for an object to be heated must be defined before a start of a heating operation. For example, to defrost a frozen meat in an electronic oven, it is desirable to heat for 30 minutes using a low power of about 250 W as a first step, then stop heating about 30 minutes as a second step to allow time for the temperature of the meat become uniform. As a final third stage, the defrosted meat is heated with a high output power of about 700 W for 10 minutes. Such a complex heating sequence is, in conventional heating apparatus, preset by a keyboard entries, namely by pushing an output power selecting key and a time key alternately. Therefore keying operation becomes comparatively complex, and sometimes a user must input the heating sequence again when the entered data is in error, or when the heating object is overheated when the user is not aware of a malfunction.
Generally speaking, when the user operates the heating apparatus to heat some foods, the user's hand is sometimes wet or oily etc. from food preparation. Since the user must touch the operating panel of the apparatus the panel may become oily or wet. This enhances the probability that a user may get an electrical shock.
One effort to overcome such disadvantages, provided an automatic electric oven of the card reader type which reads a cooking card comprising a magnetic band preliminarily written with a heating sequence. However, the electric oven of such type sometimes missread the cooking card that had become stained or wet. Also if the user lost a cooking card it was not possible to use that heating sequence. Therefore, the card reader type apparatus was not satisfactory.
In recent years, attempts have been made to introduce recorded voice, letters or words, signs or picture as an aid or guide in communicating input commands into electronics system, in order to attain easier and more natural interaction between the user and the apparatus. Especially, the use of voice is attracting much attention as a most natural communication medium between man and machine, and the use of the voice in the apparatus becomes more and more practical as semiconductor technology develops to provide increasing speeds and increases of memory capacity through higher integrations in the device, and through appearance of microcomputors used as a controlling units, etc.
The present invention purposes to comply with the technology into a heating apparatus. Applicants recognize that the present state of the art of voice recognition does not always provide a perfectly accurate result even though the number of users to be voice recognized is limited, and therefore, they provide not only the improvement in the voice recognition system hard ware, but also provide an overall arrangement providing enhanced safe operation so as to prevent fatal accidents such as may result from overheating due to misrecognition by the voice recognition circuit. That is, since the heating apparatus includes an electric heater or a microwave heating system, when an erroneous operation of the apparatus without a load therein (object to be heated) is carried out, then an enclosure case or a door of the apparaatus becomes heated to a high temperature, thereby causing a liability of burning on the user's hand or further a fire, or at least a damaging of the enclosure case or door or microwave oscillator, heater or other elements.